630740 O-Ring Seal for Main Jet Fuel Mixture Adjustment Screw | JLM Marine

630740 O-Ring Seal for Main Jet Fuel Mixture Adjustment Screw | JLM Marine

This high-quality O-ring seal is designed for the main jet fuel mixture adjustment screw in Tecumseh carburetors. It ensures a proper seal to prevent fuel leaks and maintain optimal engine performance. Compatible with a wide range of Tecumseh carburetor models including CA-630795A, CA-630812A, CA-630872A, CA-630888, CA-630892, CA-630893, CA-630894, CA-630895, CA-630911, CA-630912, CA-630920, CA-630950, CA-630950A, CA-630958B, CA-630961, CA-630961A, CA-630962, CA-630962A, CA-630964B, CA-630969, and other models. Also suitable for most S-200, S-620, Snowmaster, and Snowmaster20 snowblowers.

This aftermarket replacement directly replaces Tecumseh 630740, Rotary 146, and Sierra 7-02166-2, providing reliable performance at an excellent value.

• Precision-engineered seal for carburetor fuel mixture adjustment screws
• Package includes 15 O-ring seals for multiple repairs or maintenance
• Easy installation for quick carburetor servicing

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Fits the Following Tecumseh Carburetors:

CA-630795A, CA-630812A, CA-630872A, CA-630888, CA-630892, CA-630893, CA-630894, CA-630895, CA-630911, CA-630912, CA-630920, CA-630950, CA-630950A, CA-630958B, CA-630961, CA-630961A, CA-630962, CA-630962A, CA-630964B, CA-630969, and other models.

Also Compatible With:

Most S-200, S-620, Snowmaster, and Snowmaster20 snowblowers.

Technical Specifications

Package Contents

Your package includes:

• 15 × O-Ring Seals for Main Jet Fuel Mixture Adjustment Screw (Tecumseh 630740)

Installation Guide

1. Ensure the engine is off and cool before beginning any carburetor work.
2. Remove the carburetor from the engine following your equipment's service manual.
3. Locate the main jet fuel mixture adjustment screw on the carburetor body.
4. Carefully unscrew and remove the fuel mixture adjustment screw. Note the number of turns for reassembly.
5. Remove the old O-ring seal from the adjustment screw groove.
6. Clean the screw and groove area thoroughly to remove any debris or old seal residue.
7. Install the new O-ring seal onto the adjustment screw, ensuring it sits properly in the groove.
8. Apply a small amount of clean fuel or oil to the O-ring to aid installation.
9. Reinstall the adjustment screw, turning it in gently until it seats, then back it out the same number of turns noted earlier.
10. Reinstall the carburetor onto the engine and reconnect all fuel lines and linkages.
11. Start the engine and check for fuel leaks around the adjustment screw area.
12. Adjust the fuel mixture as needed per your equipment's specifications for optimal performance.

Troubleshooting & FAQ

Q: How do I know if this O-ring fits my Tecumseh carburetor?
A: Check your carburetor model number against the compatible list provided above (CA-630795A, CA-630812A, CA-630872A, etc.). This O-ring replaces Tecumseh 630740, Rotary 146, and Sierra 7-02166-2, so if your parts manual references any of these numbers, this seal will fit.

Q: Why is fuel leaking from my carburetor adjustment screw?
A: A worn or damaged O-ring seal is the most common cause of fuel leaks around the mixture adjustment screw. Replacing the O-ring with this part should resolve the issue. Ensure the screw is not overtightened, as this can damage the new seal.

Q: How often should I replace this O-ring seal?
A: Replace the O-ring whenever you perform carburetor maintenance or rebuild, or immediately if you notice fuel leaking from the adjustment screw area. Regular replacement during seasonal servicing helps prevent fuel system issues.

Q: Can I reuse the old O-ring if it looks okay?
A: It's not recommended. O-rings can develop micro-cracks and lose elasticity over time, even if they appear intact. Always use a new O-ring during carburetor service to ensure a proper seal and prevent future leaks.

Q: Is this an OEM part or aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.